1. Field of the Invention
The present invention relates to a recording/reproducing apparatus for reproducing information from a first recording medium such as a compact disc (hereinafter abbreviated as CD), on which main information such as music information and control (subcode) information such as music number and time information are recorded, and for recording the main information on a second recording medium, such as a magnetic tape, along with subcode information such as a program start signal.
2. Description of the Related Art
Dubbing apparatus for recording (dubbing) information such as music signals prerecorded on a CD or the like onto a magnetic tape are disclosed in Japanese Patent Unexamined Publication Nos.JP-A 63-70973 (1988) and JP-A 1-251361 (1989). One such dubbing apparatus comprises, as shown in FIG. 1, a CD player section 31 and a digital magnetic tape recorder section 32 interconnected via a terminal 33.
In the CD player section 31, a signal detected by an optical pickup 34 is amplified by an RF amplifier, 35 and is fed to a signal processing circuit 36 to extract a digital signal such as an audio signal. In some apparatus, the digital signal from the signal processing circuit 36 is directly output from the CD player section 31, but in most apparatus, the digital signal is converted to an analog signal by a D/A converter 37 for output at the terminal 33 so that the signal can also be supplied to an audio output terminal (not shown).
In the digital magnetic tape recorder section 32, the analog signal transferred through the terminal 33 is converted by an A/D converter 38 into a digital signal which is then fed to a signal processing circuit 39 where such processing as modulation and the addition of subcode information, etc. is performed. The signal from the signal processing circuit 39 is amplified by an amplifier 40 for recording on a magnetic tape (not shown) by means of a magnetic head 41.
In the thus constructed dubbing apparatus, in order to record a start ID automatically, a level sensor 42 is used to detect the level of the analog audio signal supplied from the CD player section 31. For example, when the sound level lower than -6OdB continues, for example, for 3 seconds or more (this level somewhat varies from one apparatus to another but is set to practically optimum level), the level sensor 42 determines that it is an intermusic space, and when a signal is detected after that, the level sensor 42 determines that it is the beginning of music, and provides a detection signal to the signal processing circuit 39. The signal processing circuit 39 performs control so that the start ID is recorded on the magnetic tape in response to the detection signal supplied from the level sensor 42.
In the dubbing apparatus shown in FIG.2, the signal processing circuit 36 in the CD player section 31 is so configured that the CD subcode information is provided to a terminal 44. To this terminal 44 is connected a beginning-of-music detector 43 in the digital magnetic tape recorder section 32. Based on the subcode information, the beginning-of-music detector 43 detects the position where the music number changes or where the music playing time becomes zero, determines such detected position as the beginning of music, and provides a detection signal to the signal processing circuit 39. The signal processing circuit 39 performs control so that the start ID is recorded on the magnetic tape in response to the detection signal supplied from the beginning-of-music detector 43.
In the dubbing apparatus of FIG.1, a change in the audio signal level is detected during producing of a CD by the CD player section 31, and after determining the change as the beginning of music, the signal processing circuit 39 outputs a start ID control signal for recording of the start ID. Therefore, the signal processing circuit 39 must perform arithmetic processing between the time the change is detected and the time the start ID is recorded, which causes a delay in the timing of recording the start ID. In other words, the start ID is recorded at a position past the correct music beginning position, the resulting problem being that a dropout of sound occurs in the beginning of music when reproducing the music by using the start ID.
The dubbing apparatus of FIG.2 has a similar problem to that of the foregoing apparatus of FIG.1. It has the further problem that the subcode information recorded on the CD cannot be utilized effectively.